1. Field
The embodiment relates to a light emitting device, a method of manufacturing the same, a light emitting device package, and a lighting system.
2. Background
A light emitting device (LED) includes a p-n junction diode having a characteristic of converting electric energy into light energy. The p-n junction diode can be formed by combining group III-V elements of the periodic table. The light emitting device can represent various colors by adjusting the compositional ratio of compound semiconductors.
When forward voltage is applied to the LED, electrons of an n layer are bonded with holes of a p layer, so that energy corresponding to an energy gap between a conduction band and a valance band may be generated. This energy is mainly realized as heat or light, and the LED emits the energy as the light.
For example, a nitride semiconductor represents superior thermal stability and wide band gap energy so that the nitride semiconductor has been spotlighted in the field of optical devices and high-power electronic devices. In particular, blue, green, and UV light emitting devices employing the nitride semiconductor have already been developed and extensively used.
According to the relate art, the surface texturing is used based on etching in order to improve light extraction efficiency. However, the reliability of a device and light emitting efficiency are lowered due to the damage to a GaN epitaxial layer caused by the etching.
Further, the surface texturing based on the etching degrades the reproduction.